Management of overactive bladder

Investigation of urodynamic characteristics and bladder sensory function in the early stages of diabetic bladder dysfunction in women with type 2 diabetes

PURPOSE

We studied urodynamic characteristics and bladder sensory function in the early stages of diabetic bladder dysfunction in diabetic women.

MATERIALS AND METHODS

A total of 86 consecutive type 2 diabetic women with minimal confounders of voiding dysfunction followed at a diabetes clinic were prospectively enrolled and subjected to urodynamic studies. The sensory response of Adelta and C fibers of the bladder was measured by intravesical current perception threshold testing at frequencies of 250 and 5 Hz, respectively.

RESULTS

Of these 86 women 30 (34.9%) were classified as having detrusor underactivity, 12 (14.0%) presented signs of detrusor overactivity, 11 (12.8%) were referred to as having bladder outlet obstruction and 33 (38.4%) showed normal detrusor function on urodynamics. The normal detrusor function group was the reference group. The detrusor underactivity group showed impaired emptying function and decreased sensation on cystometry and intravesical current perception threshold testing. The detrusor overactivity group showed impaired storage and emptying function but had no significant changes in intravesical current perception threshold values. When the normal detrusor function group and detrusor underactivity group were pooled to perform multivariate analysis, an increase in current perception threshold values was associated with a decrease in bladder voiding efficiency on 5 and 250 Hz current perception threshold testing.

CONCLUSIONS

Our data provide the electrophysiological evidence that indicates an association between impaired Adelta as well as C fiber bladder afferent pathways and poor emptying function in diabetic women with detrusor underactivity. Diabetes can affect the bladder presumably via peripheral pathogenetic mechanisms to induce detrusor overactivity with impaired contractility.

Preserving cognitive function for patients with overactive bladder: evidence for a differential effect with darifenacin

BACKGROUND

Antimuscarinic agents used in the treatment of overactive bladder (OAB) differ in their potential to impair cognitive function. It is hypothesised that low brain concentrations and relatively low selectivity for the M(1) muscarinic receptor may reduce the potential for adverse central nervous system (CNS) effects with darifenacin, compared with other antimuscarinics, particularly oxybutynin.

METHODS

Cognitive function studies evaluating darifenacin, oxybutynin, tolterodine, solifenacin and/or trospium were identified from publications databases (Medline, Biosis and Embase) and congress abstracts. Preclinical studies and randomised controlled trials in adults were reviewed.

RESULTS

Five randomised, double-blind, multiple-dose studies of cognitive function were identified. Oxybutynin was consistently associated with cognitive deficit (four studies), whereas darifenacin did not impair cognition (three studies). These findings were supported by data from sleep/attention and EEG studies. Tolterodine data were limited to one small study with each formulation. For solifenacin and trospium, there were no human studies evaluating memory, the cognitive function most vulnerable to CNS anticholinergics.

CONCLUSIONS

There is compelling evidence of cognitive impairment with oxybutynin, whereas darifenacin stands out by demonstrating no impairment of memory or other cognitive functions in three randomised, controlled trials. This may be attributed to the differences in physicochemical properties, efflux mechanisms and relative M(1) muscarinic receptor sparing. The risk of CNS impairment is of particular concern for vulnerable populations such as the elderly (a substantial proportion of the OAB population), and CNS-compromised neurogenic bladder patients such as those with multiple sclerosis or Parkinson's disease.

Short-term efficacy of botulinum toxin a for refractory overactive bladder in the elderly population

PURPOSE

We determined the efficacy of intravesical botulinum toxin A injection for refractory overactive bladder in elderly patients.

MATERIALS AND METHODS

Patients 75 years or older with refractory urinary urgency were prospectively evaluated and offered treatment of symptoms with botulinum toxin A. A voiding log was obtained and urodynamics were performed before treatment. Patients underwent injection of 200 U botulinum toxin A (Botox(R)) into the detrusor muscle at 20 sites under cystoscopic guidance. Patients were followed postoperatively for evidence and duration of success, and treatment related complications.

RESULTS

From January 2006 to June 2007, 18 females and 3 males with a mean age of 81.2 years (range 75 to 92) in whom detrusor overactivity was confirmed on urodynamics and who were refractory to or intolerant of antimuscarinics were treated with intravesical botulinum toxin A. Preoperatively the mean +/- SD number of daily voids was 11.4 +/- 1.67 and the mean number of pads per day was 4.0 +/- 0.89. One month after treatment 16 of the 21 patients (76%) reported greater than 50% improvement in symptoms after 1 injection. Specifically there was a significant improvement in the mean number of voids per day (5.19 +/- 0.83, p <0.001) and in the number of pads used daily (1.3 +/- 0.60, p <0.001). Two of the remaining 5 patients demonstrated greater than 50% improvement following repeat injection, while 3 did not show improvement after 2 injections. Mean time to deterioration was 7.12 months. There were no treatment related complications.

CONCLUSIONS

Intravesical botulinum toxin A for detrusor overactivity in the elderly population appears to be efficacious and durable. Given its low incidence of adverse events, it should be considered a viable treatment option in this population.

Reproductive factors associated with nocturia and urinary urgency in women: a population-based study in Finland

OBJECTIVE

The objective of this study was to evaluate the association of nocturia and urinary urgency with reproductive factors, including parity, the postpartum period, the menopause, hormone replacement therapy, hysterectomy, and surgery for stress urinary incontinence (SUI).

STUDY DESIGN

In 2003-2004, questionnaires eliciting urinary symptoms, reproductive factors, SUI surgery, and potential confounders were mailed to 3000 randomly selected women aged 18-79 years, identified from the Finnish Population Register. Nocturia was defined as 2 or more voids/night. Sudden compelling desire to urinate often or always (scale of never, rarely, often, always) was regarded as urgency. Pregnant and puerperal (6 weeks after delivery) women and those reporting urinary tract infection were excluded.

RESULTS

Responses totaled 2002 (67%). Parity, postpartum (defined as six weeks to one year after delivery) and postmenopausal periods were associated with increased nocturia and SUI surgery with increased urgency (adjusted for age, comorbidity, medication, anthropometric, sociodemographic and lifestyle factors). Hormone therapy and hysterectomy were associated with neither symptom.

CONCLUSION

Reproductive factors associated with nocturia differed from those related to urgency.

Pharmacologic evaluation of pressor and visceromotor reflex responses to bladder distension

AIMS

Several mechanisms that are involved in acute rat bladder nociception were examined. The nociceptive response was measured by analyzing both cardiovascular and visceromotor reflex responses to urinary bladder distension. The contributions of micro-opioid receptor, kappa-opioid receptor, sodium channels, muscarinic receptors, and cyclooxygenase, were explored with morphine, U50,488, mexiletine, oxybutynin, and naproxen, respectively.

METHODS

Female Sprague-Dawley rats were acutely instrumented with jugular venous, carotid arterial, and bladder cannulas. Needle electrodes were placed directly into the abdominal musculature to measure myoelectrical activity subsequent to repeated phasic urinary bladder distension (60 mmHg for 20 sec in 3 min intervals) under 1% isoflurane. Drugs were administered by i.v. bolus injection 2 min prior to distension.

RESULTS

The analgesics morphine (ID50 0.69 mg/kg), U50,488 (1.34 mg/kg), and mexiletine (2.60 mg/kg) significantly inhibited the visceromotor reflex response to noxious urinary bladder distension. Oxybutynin also attenuated reflex responses to noxious urinary bladder distension to 41% of the maximal pressor response and 32% of the control visceromotor reflex response (3.01 and 5.05 mg/kg), respectively, indicating a role of muscarinic receptors in bladder nociception. Naproxen did not attenuate the pressor response, but moderately inhibited visceromotor reflex to 45% of control at 30 mg/kg (P < 0.05).

CONCLUSIONS

Current results using the rat urinary bladder distension model are consistent with previous research demonstrating a role of the analgesics (morphine, U50,488, and mexiletine) in the inhibition of visceral nociceptive transmission. The utility of the reflex responses to urinary bladder distension may provide a method useful to examine mechanisms which target the bladder sensory pathway.

Population based study of incidence and predictors of urinary incontinence in black and white older adults

PURPOSE

We determined the incidence and predictors of incident urinary incontinence over 3 years in community dwelling older adults.

MATERIALS AND METHODS

A population based, prospective cohort study was conducted with a random sample of Medicare beneficiaries stratified to be 50% black, 50% men and 50% rural. In-home baseline assessment included standardized questionnaires and short physical performance battery. Three annual followup interviews were conducted by telephone. Incontinence was defined as any degree of incontinence occurring at least once a month in the last 6 months.

RESULTS

Participants were 490 women and 496 men 65 to 106 years old (mean age 75). Prevalence of incontinence at baseline was 41% in women and 27% in men. Three-year incidence of incontinence was 29% (84 of 290) in women and 24% (86 of 363) in men. There were no differences by race in prevalent or incident incontinence. In multivariable logistic regression models for women, significant independent baseline predictors of new incontinence included stroke (OR 3.4, p = 0.011), less than monthly incontinence (OR 3.3, p = 0.001), past or current postmenopausal estrogen (OR 2.3, p <0.006), slower time to stand from a chair 5 times (OR 1.3, p <0.045) and higher Geriatric Depression Scale Score (OR 1.2, p = 0.016). For men significant independent baseline predictors of new incontinence included less than monthly incontinence (OR 4.2, p <0.001) and lower score on the composite Physical Performance Score (OR 1.2, p <0.001).

CONCLUSIONS

Prevalence of incontinence among community dwelling older adults was high with an additional 29% of women and 24% of men reporting incident incontinence over 3 years of followup. Infrequent incontinence is a strong risk factor for developing at least monthly incontinence in both men and women.

Dual use of bladder anticholinergics and cholinesterase inhibitors: long-term functional and cognitive outcomes

OBJECTIVES

To determine the cognitive and functional consequences of dual use of cholinesterase inhibitors (ChIs) and the bladder anticholinergics oxybutynin or tolterodine.

DESIGN

Prospective cohort study.

SETTING

Nursing homes (NHs) in the state of Indiana.

PARTICIPANTS

Three thousand five hundred thirty-six Medicaid-eligible NH residents aged 65 and older taking a ChI between January 1, 2003, and December 31, 2004. Residents were excluded if they were taking an anticholinergic other than oxybutynin or tolterodine.

MEASUREMENTS

Indiana Medicaid claims data were merged with data from the Minimum Data Set (MDS). Repeated-measures analyses were performed to assess the effects of dual therapy on change in cognitive function measured using the MDS Cognition Scale (MDS-COGS; scored 0-10) and change in activity of daily living (ADL) function using the seven ADL items in the MDS (scored 0-28). Potential covariates included age, sex, race, number of medications, and Charlson Comorbidity Index score.

RESULTS

Three hundred seventy-six (10.6%) residents were prescribed oxybutynin or tolterodine concomitantly with a ChI. In residents in the top quartile of ADL function, ADL function declined an average of 1.08 points per quarter when not taking bladder anticholinergics (ChI alone), compared with 1.62 points per quarter when taking dual therapy, a 50% greater rate in quarterly decline in ADL function (P=.01). There was no excess decline attributable to dual therapy in MDS-COGS scores or in ADL function for residents who started out with lower functioning.

CONCLUSION

In higher-functioning NH residents, dual use of ChIs and bladder anticholinergics may result in greater rates of functional decline than use of ChIs alone. The MDS-COGS may not be sensitive enough to detect differences in cognition due to dual use.

In vivo quantitative autoradiographic analysis of brain muscarinic receptor occupancy by antimuscarinic agents for overactive bladder treatment

We evaluated the effects of five clinically used antimuscarinic agents for overactive bladder (OAB) treatment on in vivo muscarinic receptor binding in rat brain by quantitative autoradiography. There was a dose-related decrease in in vivo specific +N-[11C]methyl-3-piperidyl benzilate ([11C](+)3-MPB) binding in each brain region of rats 10 min after i.v. injection of oxybutynin, propiverine, solifenacin, and tolterodine. Rank order of the i.v. dose for 50% receptor occupancy (RO(50)) of antimuscarinic agents in rat brain regions was propiverine > solifenacin > tolterodine, oxybutynin. There was a good linear relationship between in vivo (pRO(50) values in the rat hippocampus) and in vitro (pK(i) values in human M(1) receptors) receptor binding activities of propiverine, solifenacin, and tolterodine. The observed RO(50) value of oxybutynin was approximately five times smaller than the predicted in vitro K(i) value. The dose ratios of antimuscarinic agents for the brain receptor occupancy (RO(50)) to the inhibition of carbachol- and volume-induced increases in intravesical pressure (ID(50)), which reflects in vivo selectivity for the urinary bladder over the brain, were greater for solifenacin, tolterodine, and propiverine than oxybutynin. Darifenacin displayed only a slight decrease in specific [11C](+)3-MPB binding in the rat brain regions, and it was not dose-related. In conclusion, in vivo quantitative autoradiographic analysis of brain muscarinic receptor occupancy may provide fundamental basis for managing central nervous system (CNS) side effects in antimuscarinic therapy for OAB. It is suggested that in the treatment of OAB, CNS side effects can be avoided by antimuscarinic agents with high selectivity for the urinary bladder over the brain.

Pediatric overactive bladder syndrome: pathophysiology and management

Detrusor overactivity, also known as the overactive bladder syndrome (OAB), urge syndrome, hyperactive bladder syndrome, persistent infantile bladder, and detrusor hypertonia, is the most common voiding dysfunction in children. Until recently, the concepts that had been used to dictate the management of this problem in children were based on the foundation that this was a primary bladder problem and or a delay in maturation in the nervous system of children. The expectation that children would outgrow their problems led many pediatric urologists and other practitioners to tell the parents of these children 'that they would not be wetting themselves on their wedding day.' However, it has become apparent from recent studies in adult patients with voiding dysfunctions that they had symptoms present as children. Recent findings of associations between lower urinary tract symptoms and sexual dysfunction and between voiding dysfunctions and neuropsychiatric problems have opened up a new frontier into the possible mechanisms of OAB in children that would explain these problems, link them together, and explain the continued problems that adult patients face. These findings point to OAB as a symptom of a more centrally located dysfunction that affects multiple systems. The objective of this review was to evaluate the neuroanatomy and neurophysiology of voiding and neuropharmacologic effects. We considered not only the available research and clinical data within the urologic field but also outside the field so that these data could be combined to generate a unified theory that could possibly explain many of the associated symptoms that are commonly found in pediatric OAB. Treatment modalities that are currently available for managing OAB were also explored. Currently available data indicate that pediatric OAB and many pediatric voiding dysfunctions may be part of a more generalized problem that affects multiple systems: notably bowels, bladder, sexual and ejaculatory function, control of blood pressure, and even mood and behavior. We explain the relationship that the bowel has with pediatric OAB and also the link that other neuropsychiatric problems have with OAB. This article describes which drug may be best suited to treat OAB in children and what treatment modalities are available when first-line drugs fail. In conclusion, the movement away from a vesicocentric way of thinking to a more corticocentric mode of thinking along with new imaging modalities that can examine the brain as it works will be of great value in determining future treatments of OAB. Medications generated from these evidence-based studies will hopefully treat the underlying disease process and not just the symptoms.

Inducible knockout mutagenesis reveals compensatory mechanisms elicited by constitutive BK channel deficiency in overactive murine bladder

The large-conductance, voltage-dependent and Ca(2+)-dependent K(+) (BK) channel links membrane depolarization and local increases in cytosolic free Ca(2+) to hyperpolarizing K(+) outward currents, thereby controlling smooth muscle contractility. Constitutive deletion of the BK channel in mice (BK(-/-)) leads to an overactive bladder associated with increased intravesical pressure and frequent micturition, which has been revealed to be a result of detrusor muscle hyperexcitability. Interestingly, time-dependent and smooth muscle-specific deletion of the BK channel (SM-BK(-/-)) caused a more severe phenotype than displayed by constitutive BK(-/-) mice, suggesting that compensatory pathways are active in the latter. In detrusor muscle of BK(-/-) but not SM-BK(-/-) mice, we found reduced L-type Ca(2+) current density and increased expression of cAMP kinase (protein kinase A; PKA), as compared with control mice. Increased expression of PKA in BK(-/-) mice was accompanied by enhanced beta-adrenoceptor/cAMP-mediated suppression of contractions by isoproterenol. This effect was attenuated by about 60-70% in SM-BK(-/-) mice. However, the Rp isomer of adenosine-3',5'-cyclic monophosphorothioate, a blocker of PKA, only partially inhibited enhanced cAMP signaling in BK(-/-) detrusor muscle, suggesting the existence of additional compensatory pathways. To this end, proteome analysis of BK(-/-) urinary bladder tissue was performed, and revealed additional compensatory regulated proteins. Thus, constitutive and inducible deletion of BK channel activity unmasks compensatory mechanisms that are relevant for urinary bladder relaxation.

Patient perspectives in the management of overactive bladder, focus on transdermal oxybutynin

Overactive bladder syndrome (OAB) is a constellation of distressing symptoms that significantly impair quality of life, sexual function, and work productivity, and imposes a significant economic burden to society. Pharmacological treatment with antimuscarinic agents, behavioral modification, bladder retraining, and/or pelvic floor exercises are often used alone or in combination as the mainstay treatment in the management of OAB. Oxybutynin has been used in the treatment of OAB for over 20 years with proven efficacy and is often the comparator in drug treatment trials. Oral formulations of oxybutynin have proven efficacy, but not without significant antimuscarinic effects, which reduce patient persistence with medical treatment. Low levels of patient persistence with oral formulations of oxybutynin provided an impetus for the development of a transdermal oxybutynin delivery system. The oxybutynin transdermal formulation has been found to have side effects similar to that of a placebo in randomized controlled trials while providing excellent efficacy. Patient persistence with therapy, improved quality of life, sexual function and interpersonal relationships have been observed with use of the transdermal oxybutynin delivery system. Its twice weekly dosing, low side effect profile, and high efficacy have made it a good choice for initial treatment of overactive bladder syndrome.

Therapeutic receptor targets for lower urinary tract dysfunction

The functions of the lower urinary tract, to store and periodically release urine, are dependent on the activity of smooth and striated muscles in the bladder, urethra, and external urethral sphincter. During urine storage, the outlet is closed, and the bladder smooth muscle is quiescent. When bladder volume reaches the micturition threshold, activation of a micturition center in the dorsolateral pons (the pontine micturition center) induces a bladder contraction and a reciprocal relaxation of the urethra, leading to bladder emptying. During voiding, sacral parasympathetic (pelvic) nerves provide an excitatory input (cholinergic and purinergic) to the bladder and inhibitory input (nitrergic) to the urethra. These peripheral systems are integrated by excitatory and inhibitory regulation at the levels of the spinal cord and the brain. Injury or diseases of the nervous system, as well as drugs and disorders of the peripheral organs, can produce lower urinary tract dysfunction. In the overactive bladder (OAB) condition, therapeutic targets for facilitation of urine storage can be found at the levels of the urothelium, detrusor muscles, autonomic and afferent pathways, spinal cord, and brain. There is increasing evidence showing that the urothelium has specialized sensory and signaling properties including: (1) expression of nicotinic, muscarinic, tachykinin, adrenergic, bradykinin, and transient receptor potential (TRP) receptors, (2) close physical association with afferent nerves, and (3) ability to release chemical molecules such as adenosine triphosphate (ATP), acetylcholine, and nitric oxide. Increased expression and/or sensitivity of these urothelial-sensory molecules that lead to afferent sensitization have been documented as possible pathogenesis of OAB. Targeting afferent pathways and/or bladder smooth muscles by modulating activity of ligand receptors (e.g., neurokinin, ATP, or beta3-adrenergic receptors) and ion channels (e.g., TRPV1 or K) could be effective to suppress OAB. In the stress urinary incontinence condition, pharmacotherapies targeting the neurally mediated urethral continence reflex during stress conditions such as sneezing or coughing could be effective for increasing the outlet resistance. Therapeutic targets include adrenergic and serotonergic receptors in the spinal cord as well as adrenergic receptors at the urethral sphincter, which can enhance urethral reflex activity during stress conditions and increase baseline urethral pressure, respectively.

Amikacin: A Novel Modulator of Vesical and Prostate Efferences. An in vitro Experimental Study

The autonomic efferent neurotransmission to the bladder and prostate smooth muscle is a potential target for drug therapy of specific low urinary tract disfunction (LUTD). Since amikacin and other amynoglicosides were reported to affect neurotransmission by a pre-junctional mechanism, we investigated the effect of amikacin on isolated rat and human detrusor smooth muscle contraction and on isolated rat and human prostate contraction, to further evaluate its potential relaxant properties.

Materials and Methods

Samples of detrusor smooth muscle and prostate tissue, obtained from 97 rats and 16 patients undergoing surgery, were studied through the measurement of isometric contraction induced by electrical field stimulation (EFS) and other pharmacological stimuli in the presence or absence of 1mM amikacin in a low-Ca medium.

Results

Amikacin 1 mM significantly reduced contraction of isolated rat and human detrusor muscle and prostate, achieved with pre-junctional stimulation, while no significant effect was observed on contraction induced by pharmacological post-junctional stimulators. EFS contraction inhibited by amikacin was restored after addition of calcium chloride. The amikacin effect was comparable to the effect of magnesium ions, which are known to exert a pre-junctional inhibition of neurotransmitter release.

Conclusions

Amikacin significantly inhibited rat and human detrusor and prostate contraction evoked by pre-junctional stimulation in vitro, suggesting a depressant effect on autonomic efferent neurotransmission. Further pharmacokinetics studies and researches on related compounds may hold potential for future development in the treatment of specific low urinary tract disfunction (LUTD).

Overactive Bladder in Children. Part 1: Pathophysiology

PURPOSE

Detrusor overactivity is the most common voiding dysfunction in children. Detrusor overactivity is also known as overactive bladder syndrome, urge syndrome, hyperactive bladder syndrome, persistent infantile bladder and detrusor hypertonia. It has become apparent that the ideas that had been used to dictate the management of this problem in children were based on the foundation that this is a primary bladder problem and/or a delay in maturation in the nervous system of children. The expectation that children would outgrow the problems led many pediatric urologists and other practitioners to tell the parents of these children that they would not be wetting themselves on their wedding day. It has become apparent from recent studies in adults with voiding dysfunction that they had symptoms present as children. The recent findings of associations with lower urinary tract symptoms and sexual dysfunction, and the association of voiding dysfunction and neuropsychiatric problems has opened up a new frontier into the possible mechanisms of overactive bladder syndrome in children that would explain these problems, tie them together and explain the continued problems that adults face. These findings point to overactive bladder syndrome as a symptom of a more centrally located dysfunction that affects multiple systems, notably bowels, bladder, sexual and ejaculatory function, control of blood pressure, and even mood and behavior.

MATERIALS AND METHODS

We looked at the neuroanatomy, neurophysiology and neuropharmacology of voiding. Available research and clinical data in the urological field as well as outside of the field were combined to generate a unified theory that could possibly explain many associated symptoms that are commonly found in pediatric overactive bladder syndrome.

RESULTS

The available data indicate that pediatric overactive bladder syndrome and many pediatric voiding dysfunctions may be part of a more generalized problem that affects multiple systems, notably bowels, bladder, sexual and ejaculatory function, control of blood pressure, and even mood and behavior. We explained the relationship that the bowel has with pediatric overactive bladder syndrome and also the link that other neuropsychiatric problems have with overactive bladder syndrome.

CONCLUSIONS

The movement away from a vesicocentric way of thinking to a more corticocentric mode of thinking along with new imaging modalities that can look at the brain and examine it as it works will be of great value for determining future treatments. Medications generated from these evidence based studies will hopefully treat the underlying disease process and not just the symptoms.

Beyond the Bladder: Management of Urinary Incontinence in Older Women

Unlike urinary incontinence (UI) in younger women, UI in older women is usually multifactoral in etiology and involves factors beyond the more common types of lower urinary tract (LUT) pathophysiology associated with UI in younger women. The evaluation and management of UI in older women, therefore, must itself be multifactoral and sometimes multidisciplinary, and encompass an understanding of age-related LUT changes, age-specific LUT pathophysiology, and a broadened, multidimensional concept of continence.

A practical guide to the evaluation and treatment of male lower urinary tract symptoms in the primary care setting

AIMS

Lower urinary tract symptoms (LUTS) are common in both men and women, and are among the most prevalent patient complaints heard by primary care physicians (PCPs). This article aims to provide PCPs with a logical algorithm for the assessment and initiation of treatment for LUTS in the male patient.

RESULTS

Management of LUTS involves a focused history and physical, as well as the assessment of bother. In patients for whom treatment is warranted, a series of decisions regarding therapy should be considered. Male patients commonly suffer from storage and/or voiding symptoms. Treatment of male LUTS is commonly begun with agents that are aimed at remedying the outlet symptoms of benign prostatic hyperplasia (BPH). When this intervention is ineffective or when refractory symptoms persist, consideration should be given to treating the storage symptoms characteristic of overactive bladder (OAB).

DISCUSSION

This article is intended to provide the PCP with a logical guide to the treatment of male LUTS. Benign prostatic hyperplasia and OAB predominate among the causes of these symptoms, and the PCP should be comfortable treating each. Recent data detailing the safety of the use of these treatments in the male patient are reviewed and incorporated into the algorithm.

CONCLUSION

Primary care physicians are in a unique position to successfully identify and treat male patients with LUTS. With this paper, they now have a tool to approach treatment logically and practically.

Overactive bladder treatments in early phase clinical trials

'Overactive bladder' (OAB) is a syndrome that is characterised by symptoms of urgency, with or without urge urinary incontinence, usually with frequency and nocturia [1] . It is a highly prevalent condition affecting 17% of the general population, with a significant negative effect on quality of life, impairing several areas with physical, social, emotional and sexual limitations. The prevalence of OAB increases with age in both men and women [2,3] . The pathophysiology is multifactorial and not yet fully understood. Non-surgical treatment is the mainstay of therapy for OAB. The available options include biofeedback, electrical stimulation, bladder training, pharmacotherapy or a combination of these options. Nevertheless pharmacotherapy is still the treatment of choice for OAB symptoms [4] . The pharmacological treatment of OAB is generally directed towards the central or the peripheral neural control pathways or the detrusor muscle [5] . The antimuscarinic drugs are the most commonly used. In the US, approved antimuscarinics include oxybutynin, tolterodine, trospium chloride, solifenacin and darifenacin. Although this class of drugs has been shown to be more effective than placebo in specific meta-analyses [6] , it has been reported that < or = 80% of the patients discontinue the treatment within 6 months, mainly for the low drug compliance due to the high incidence of side effects [7] . Therefore, there is a strong need to identify drugs with novel mechanisms of action, which could provide equal or even better efficacy and overall greater acceptability than antimuscarinic drugs. At present, several other specific molecular targets identified within detrusor muscle and/or neural systems are under investigation for the development of more specific treatments of OAB. This article provides an up-to date review of drugs that are in investigational preclinical and early stage (Phase I and II) clinical trials for the treatment of OAB.

Comparative in vivo uroselectivity profiles of anticholinergics, tested in a novel anesthetized rabbit model

The aim of this study was to describe a new experimental animal model for simultaneous measurement of carbachol-induced increase in intravesical pressure and salivary secretion in rabbits. Further, we also compared the in vivo potency and urinary bladder versus salivary gland selectivity profiles of Oxybutynin, Tolterodine, Solifenacin and Darifenacin. The intravesical pressure and salivary secretion were evoked by intra-arterial injection of carbachol (1.5 microg/kg). The carbachol-induced increase in intravesical pressure and salivation was simultaneously recorded before and after increasing doses of test drugs administered intravenously. The basal mean changes in intravesical pressure and salivation subsequent to carbachol administration were in the range of 6.7-7.5 mm Hg and 0.5-0.7 g respectively. Repeated administration of vehicle did not elicit any appreciable changes in intravesical pressure and salivary secretion to carbachol administration from the basal values till 3 h. All the test drugs exhibited a dose-dependent inhibition of carbachol-induced increase in intravesical pressure and salivary secretion. Darifenacin demonstrated a greater potency compared to other muscarinic receptor antagonists for inhibiting carbachol-induced increase in intravesical pressure. It also exhibited functional selectivity for the urinary bladder versus salivary gland. In contrast, Oxybutynin was functionally more selective in inhibiting carbachol-induced increase in salivary secretion. The observed urinary bladder versus salivary selectivity values were 0.6+/-0.2, 1.1+/-0.2, 1.7+/-0.5, and 2.3+/-0.5 for Oxybutynin, Tolterodine, Solifenacin and Darifenacin respectively. These results suggest that the functional selectivity of muscarinic receptor antagonists between urinary bladder and salivary glands can be readily detected in this model. Thus rabbits may represent a useful animal model for evaluating putative bladder selective muscarinic receptor antagonists for the treatment of overactive bladder.

Lower urinary tract symptoms and uroflowmetry in women with type 2 diabetes mellitus with and without bladder dysfunction

OBJECTIVES

To study the presence of lower urinary tract symptoms and parameters of uroflowmetry in women with type 2 diabetes mellitus with and without bladder dysfunction versus healthy controls.

METHODS

After eliminating the possible confounders that might cause bladder dysfunction, 182 female patients at a diabetic clinic were evaluated by the American Urological Association Symptom Index (AUA-SI) questionnaire and uroflowmetry with postvoid residual (PVR) urine volume estimate. Their data were compared with the data from 197 healthy women, frequency-matched by age.

RESULTS

Using a cutoff value of bladder voiding efficiency of less than 75% with a PVR greater than 50 mL but less than 100 mL, a PVR greater than 100 mL, or a total volume greater than 500 mL, 47 patients (25.8%) were stratified as having bladder dysfunction. These patients had a significantly greater mean AUA-SI score (mean +/- standard error of the mean 9.6 +/- 0.8, P <0.001), as well as a lower maximum uroflow value (15.2 +/- 1.2 mL/s, P <0.001) compared with the control groups. The odds ratio of each lower urinary tract symptom was significantly greater in this group, except for straining (P = 0.12). A high proportion with an intermittent uroflow pattern (odds ratio 4.42, P <0.001) was also noted. Compared with the healthy controls, the diabetic women had no bladder dysfunction and seemed unaffected by the lower urinary tract symptoms as defined by the AUA-SI scoring system, with the exception of nocturia (odds ratio 2.62, P = 0.006).

CONCLUSIONS

Women with diabetes may have an increased risk of nocturia even without bladder dysfunction. A high AUA-SI score and lower maximum uroflow are likely to be good markers for diabetic bladder dysfunction.

Physiology and pathophysiology of purinergic neurotransmission

This review is focused on purinergic neurotransmission, i.e., ATP released from nerves as a transmitter or cotransmitter to act as an extracellular signaling molecule on both pre- and postjunctional membranes at neuroeffector junctions and synapses, as well as acting as a trophic factor during development and regeneration. Emphasis is placed on the physiology and pathophysiology of ATP, but extracellular roles of its breakdown product, adenosine, are also considered because of their intimate interactions. The early history of the involvement of ATP in autonomic and skeletal neuromuscular transmission and in activities in the central nervous system and ganglia is reviewed. Brief background information is given about the identification of receptor subtypes for purines and pyrimidines and about ATP storage, release, and ectoenzymatic breakdown. Evidence that ATP is a cotransmitter in most, if not all, peripheral and central neurons is presented, as well as full accounts of neurotransmission and neuromodulation in autonomic and sensory ganglia and in the brain and spinal cord. There is coverage of neuron-glia interactions and of purinergic neuroeffector transmission to nonmuscular cells. To establish the primitive and widespread nature of purinergic neurotransmission, both the ontogeny and phylogeny of purinergic signaling are considered. Finally, the pathophysiology of purinergic neurotransmission in both peripheral and central nervous systems is reviewed, and speculations are made about future developments.

Changing concepts of bladder regeneration

During the last decade, there has been a dramatic increase in studies aimed at regeneration of the urinary bladder. Many studies employed animal-derived or synthetic materials as grafts for experimental bladder augmentation models, with or without additional measures to promote regeneration, such as autologous cell transplantation or growth factor loading. However, in spite of encouraging results in several reports, few methodologies have shown proven definitive clinical utility. One major problem in these studies is the lack of a clear distinction between native and regenerated bladder in total bladder function after augmentation. Another crucial problem is the absorption and shrinkage of larger grafts, which may result from insufficient vascular supply and smooth muscle regeneration. In contrast, researchers have recently attempted to establish alternative regenerative strategies for treating bladder diseases, and have employed far more diverse approaches according to the various pathological conditions to be treated. For total replacement of the bladder after cystectomy for invasive bladder cancer, urothelium-covered neobladder with non-urinary tract backbone remains a viable choice. In addition, functional bladder diseases such as urinary incontinence, weak detrusor, or non-compliant fibrotic bladder have also been major targets for many leading research groups in this field. These conditions are studied much more from different therapeutic standpoints, aiming at the prevention or reversal of pathological conditions in muscle remodeling or neural control. Such altered research direction would inevitably lead to less surgically based basic biological research, and also would include a far wider spectrum of adult and pediatric bladder diseases, from overactive bladder to dysfunctional voiding.

Office management of geriatric urinary incontinence

Urinary incontinence is a common and potentially disabling condition affecting 15% to 30% of those aged 65 years and older. It adversely affects physical health, psychological well-being, and health care costs. Even when it is not curable, proper management of urinary incontinence can lead to improved quality of life for patients and caregivers. Despite its prevalence, many geriatric patients suffering from urinary incontinence are undiagnosed and untreated. Patients often do not report the problem, and health care professionals often do not ask about it. Health care professionals should therefore learn to identify, evaluate, and manage urinary incontinence based upon the available evidence and practice guidelines. Although the evidence base for specific recommendations for the office evaluation and management of geriatric urinary incontinence is limited, a basic evaluation to identify treatable causes of incontinence, referral of appropriate patients for further evaluation, and several noninvasive management strategies can greatly improve these symptoms in many older patients.

Is the prevalence of overactive bladder overestimated? A population-based study in Finland

BACKGROUND

In earlier studies, one in six adults had overactive bladder which may impair quality of life. However, earlier studies have either not been population-based or have suffered from methodological limitations. Our aim was to assess the prevalence of overactive bladder symptoms, based on a representative study population and using consistent definitions and exclusions.

METHODOLOGY/PRINCIPAL FINDINGS

The aim of the study was to assess the age-standardized prevalence of overactive bladder defined as urinary urgency, with or without urgency incontinence, usually with urinary frequency and nocturia in the absence of urinary tract infection or other obvious pathology. In 2003-2004, a questionnaire was mailed to 6,000 randomly selected Finns aged 18-79 years who were identified from the Finnish Population Register Centre. Information on voiding symptoms was collected using the validated Danish Prostatic Symptom Score, with additional frequency and nocturia questions. Corrected prevalence was calculated with adjustment for selection bias due to non-response. The questionnaire also elicited co-morbidity and socio-demographic information. Of the 6,000 subjects, 62.4% participated. The prevalence of overactive bladder was 6.5% (95% CI, 5.5% to 7.6%) for men and 9.3% (CI, 7.9% to 10.6%) for women. Exclusion of men with benign prostatic hyperplasia reduced prevalence among men by approximately one percentage point (to 5.6% [CI, 4.5% to 6.6%]). Among subjects with overactive bladder, urgency incontinence, frequency, and nocturia were reported by 11%, 23%, and 56% of men and 27%, 38%, and 40% of women, respectively. However, only 31% of men and 35% of women with frequency, and 31% of subjects of both sexes with nocturia reported overactive bladder.

CONCLUSIONS/SIGNIFICANCE

Our results indicate a prevalence of overactive bladder as low as 8% suggesting that, in previous studies, occurrence has been overestimated due to vague criteria and selected study populations regarding age distribution and low participation.

New Options and Strategies for the Treatment of Urinary Incontinence

Urinary incontinence is a prevalent, although often unreported, disease within the elderly population, with consequences spanning many aspects of the patient's life. Treatments differ for each subtype of urinary incontinence: urge incontinence, stress incontinence, and incontinence associated with bladder outlet obstruction and lower urinary tract symptoms in men. Limitations in current therapies have negatively affected care for each of these subtypes, particularly in the vulnerable elderly population. An emergence of new treatment options and strategies has created opportunities to optimize care for the general population. These include the use of trospium, darifenacin, solifenacin, and duloxetine as well as the strategic use of antimuscarinic agents in conjunction with alpha adrenergic blockade in men with bladder outlet obstruction. Yet, the literature regarding use of these agents and strategies in the elderly should be carefully evaluated to determine the benefits and the unique risks posed by their use in this vulnerable population.

Clozapine for the treatment of neurogenic bladder

Neurogenic bladder leading to urinary incontinence has been described in patients of stroke, dementia, Parkinson's disease, and some schizophrenia cases with cognitive impairment possibly due to impaired cortical inhibition of the urinary bladder. The underlying brain abnormalities for urinary incontinence are similar in such cases. We report here such a case of neurogenic bladder responding to treatment with clozapine. The possible mechanism of action and clinical implications are described.

Lower urinary tract symptoms (LUTS) and bladder afferent activity

AIMS

Dysregulation of bladder afferent activity and detrusor smooth muscle behavior leads to a constellation of lower urinary tract symptoms (LUTS), which includes overactive bladder (OAB). Current treatments for LUTS are poorly tolerated and may be associated with substantial adverse effects.

METHODS

Major advances in the understanding of bladder neuroanatomy and the role of bladder afferent pathways in symptom generation suggest a range of targets for new therapeutic agents.

RESULTS

A sensory role for urothelial and suburothelial structures has been established, as well as a cascade of afferent bladder signaling involving the bladder epithelium and detrusor muscle. Numerous inhibitory and stimulatory neurotransmitters and chemical mediators interact with a variety of specialized receptors and participate in signal transduction leading to wider neuroactivation. The blockade of muscarinic receptors, possibly mediated by muscarinic 2 (M(2)) receptors residing in the urothelium, has been shown to affect bladder afferent fibers, challenging the traditional concept that antimuscarinic therapy involves M(3) receptor-mediated effects on detrusor smooth muscle. The propagation of impulses to spinal and higher centers utilizes axonal fiber tracts remarkable for their morphologic and functional plasticity as bladder function becomes increasingly disordered.

CONCLUSIONS

These findings suggest that the etiology of LUTS includes enhanced, dysregulated, and perhaps maladaptive sensory signaling arising from numerous pelvic locales, including the most superficial epithelium of the bladder.

Clinically important drug-disease interactions and their prevalence in older adults

BACKGROUND

Older adults may have decreased homeostatic reserve, have multiple chronic diseases, and take multiple medications. Therefore, they are at risk for adverse outcomes after receiving a drug that exacerbates a chronic disease.

OBJECTIVES

The aims of this study were to compile a list of clinically important drug-disease interactions in older adults, obtain the consensus of a multidisciplinary panel of geriatric health care professionals on these interactions, and determine the prevalence of these interactions in a sample of outpatients.

METHODS

This analysis included a 2-round modified Delphi survey and cross-sectional study. Possible drug-disease interactions in patients aged > or =65 years were identified through a search of the English-language literature indexed on MEDLINE and International Pharmaceutical Abstracts (1966-July 2004) using terms that included drug-disease interaction, medication errors, and inappropriate prescribing. Nine health care professionals with expertise in geriatrics (2 geriatricians, 7 geriatric clinical pharmacist specialists) were selected based on specialty training and continuing clinical work in geriatrics, academic appointments, and geographic location. The panel rated the importance of the potential drug-disease interactions using a 5-point Likert scale (from 1 = definitely not serious to 5 = definitely serious). Consensus on a drug-disease interaction was defined as a lower bound of the 95% CI > or =4.0. The prevalence of drug-disease interactions was determined by applying the consensus criteria to a convenience sample of frail older veterans at hospital discharge who were enrolled in a health services intervention trial.

RESULTS

The panel reached consensus on 28 individual drug-disease interactions involving 14 diseases or conditions. Overall, 205 (15.3%) of the 1340 veterans in the sample had > or =1 drug-disease interaction. The 2 most common drug-disease interactions were use of first-generation calcium channel blockers in patients with congestive heart failure and use of aspirin in patients with peptic ulcer disease (both, 3.7%).

CONCLUSIONS

A survey of multidisciplinary geriatric health care professionals resulted in a concise consensus list of clinically important drug-disease interactions in older adults. Further research is needed to examine the impact of these drug-disease interactions on health outcomes and their applicability as national measures for the prevention of drug-related problems.

Detrusor Underactivity: Clinical Features and Pathogenesis of an Underdiagnosed Geriatric Condition

Urinary incontinence and other lower urinary tract symptoms exert a major influence on the health and independence of frail older people. Detrusor underactivity (DU) is defined as a contraction of reduced strength and/or duration, resulting in prolonged bladder emptying and/or a failure to achieve complete bladder emptying within a normal time span. DU may influence the clinical presentation and impede the therapy of disorders as common and as disparate as detrusor overactivity, urinary retention, and benign prostatic hyperplasia. Urodynamically, nearly two-thirds of incontinent nursing home residents exhibit DU. The clinical diagnosis of DU when present alone or in association with other bladder conditions such as detrusor overactivity (detrusor hyperactivity with impaired contractility (DHIC)) is challenging, because symptoms lack adequate precision. A catheterized and increasingly noninvasive ultrasound-based postvoid residual assessment allows a bedside diagnosis of retention and may suggest the presence of DU in individuals (mostly women) with a low likelihood of bladder outlet obstruction (BOO). Nevertheless, it cannot differentiate primary DU from retention secondary to BOO. The management of individuals with DHIC remains unsatisfactory, because antispasmodic anticholinergic medications may worsen retention, whereas bethanechol does not improve bladder emptying. Human detrusor biopsies reveal axonal degeneration, muscle loss, and fibrosis in DU. Animal studies suggest that multiple risk factors, including retention itself, lack of estrogen, infection, inflammation, and aging, may contribute to DU. Priority areas for future research include efforts to facilitate clinical nonurodynamic diagnosis of probable DU plus translational research designed to address the pathogenesis of this complex multifactorial geriatric syndrome.

The impact of the overactive bladder syndrome on sexual function: a preliminary report from the Multicenter Assessment of Transdermal Therapy in Overactive Bladder with Oxybutynin trial

OBJECTIVE

The objective of the study was to determine the impact of overactive bladder on sexual function from a preliminary analysis of the Multicenter Assessment of Transdermal Therapy in Overactive Bladder with Oxybutynin study.

STUDY DESIGN

The Multicenter Assessment of Transdermal Therapy in Overactive Bladder with Oxybutynin study was an open-label, prospective trial of 2878 subjects with overactive bladder, treated with transdermal oxybutynin for 6 months or less. The impact of overactive bladder on sexual function before and after treatment was assessed via item responses from the King's Health Questionnaire and Beck Depression Inventory-II (kappa-test).

RESULTS

At baseline, 586 (23.1%) reported that overactive bladder had an impact on their sex life. Coital incontinence in 569 (22.8%) decreased after treatment to 438 (19.3%). Effects of overactive bladder on subjects' sex lives improved in 19.1% (worsened in 11.2%), and the effect on relationships with partners improved in 19.6% (worsened in 11.9%). Reduced interest in sex, reported by 52.1% at baseline, improved significantly. (all P < .0001).

CONCLUSION

Overactive bladder negatively affects sexual function. Treatment with transdermal oxybutynin improved sexual function and marital relationships.

Propiverine and metabolites: differences in binding to muscarinic receptors and in functional models of detrusor contraction

Propiverine is a commonly used antimuscarinic drug used as therapy for symptoms of an overactive bladder. Propiverine is extensively biotransformed into several metabolites that could contribute to its spasmolytic action. In fact, three propiverine metabolites (M-5, M-6 and M-14) have been shown to affect various detrusor functions, including contractile responses and L-type calcium-currents, in humans, pigs and mice, albeit with different potency. The aim of our study was to provide experimental evidence for the relationship between the binding of propiverine and its metabolites to human muscarinic receptor subtypes (hM(1)-hM(5)) expressed in chinese hamster ovary cells, and to examine the effects of these compounds on muscarinic receptor-mediated detrusor function. Propiverine, M-5, M-6 and M-14 bound to hM(1)-hM(5) receptors with the same order of affinity for all five subtypes: M-6 > propiverine > M-14 > M-5. In HEK-293 cells expressing hM(3), carbachol-induced release of intracellular Ca(2+) ([Ca(2+)](i)) was suppressed by propiverine and its metabolites; the respective concentration-response curves for carbachol-induced Ca(2+)-responses were shifted to the right. At higher concentrations, propiverine and M-14, but not M-5 and M-6, directly elevated [Ca(2+)](i). These results were confirmed for propiverine in human detrusor smooth muscle cells (hDSMC). Propiverine and the three metabolites decreased detrusor contractions evoked by electric field stimulation in a concentration-dependent manner, the order of potency being the same as the order of binding affinity. We conclude that, in comparison with the parent compound, loss of the aliphatic side chain in propiverine metabolites is associated with higher binding affinity to hM(1)-hM(5) receptors and higher functional potency. Change from a tertiary to a secondary amine (M-14) results in lower binding affinity and reduced potency. Oxidation of the nitrogen (M-5) further lowers binding affinity as well as functional potency.

The overactive bladder: review of current pharmacotherapy in adults. Part 2: treatment options in cases refractory to anticholinergics

In the first part of this review the potential pathophysiological factors involved in the overactive bladder were outlined, and the wide range of first-line anticholinergic pharmacotherapies available for such patients were reviewed. The second part will focus on the intravesical instillation of resiniferatoxin and injections of botulinum toxin into the bladder to treat overactive bladder and detrusor overactivity. Resiniferatoxin has been shown to increase bladder capacity and improve incontinence in patients with neurogenic and non-neurogenic detrusor overactivity. Botulinum toxin has successfully been used to treat neurogenic and idiopathic detrusor overactivity, with improvements observed in bladder capacity, decreases in detrusor pressures on filling and voiding, and increased volumes at first contraction. Further validation is required for both treatments, in the form of large randomised controlled trials, before their use can be considered routine, with particular focus on dosing required.

Urinary-catheter-associated infections in the elderly

The indwelling urinary catheter is the leading cause of complicated urinary tract infections and Gram-negative bacteraemia in this age group. It accounts for about 40% of life-threatening septicaemia. There is a progressive increase in mortality independently associated with the duration of catheterization. Polymicrobial bacteriuria is common. Urease-producing bacteria lead to encrusted and blocked catheters. The current challenges are to develop effective methods to sensitize healthcare workers to avoid the routine use of indwelling catheters, remove them when no longer needed, develop alternative methods for care of incontinence, employ non-invasive methods to measure urine output, and improve urine drainage systems. The research paradigm needs to focus on prevention of catheter-associated infections rather than on futile attempts to treat irreversible sepsis.

Neurogenic bowel and bladder in the older adult

Special skills are needed in caring for an elderly patient with a neurogenic bowel and bladder. One not only has to take into account the age-related changes that occur, but also how these changes impact on a patient already struggling with bowel and bladder issues because of various neurogenic causes. Incontinence of bowel and bladder leads to a loss of quality of life and physicians should be educated on the treatment available to provide the best care for their patients.

Purinergic P2 receptors as targets for novel analgesics

Following hints in the early literature about adenosine 5'-triphosphate (ATP) injections producing pain, an ion-channel nucleotide receptor was cloned in 1995, P2X3 subtype, which was shown to be localized predominantly on small nociceptive sensory nerves. Since then, there has been an increasing number of papers exploring the role of P2X3 homomultimer and P2X2/3 heteromultimer receptors on sensory nerves in a wide range of organs, including skin, tongue, tooth pulp, intestine, bladder, and ureter that mediate the initiation of pain. Purinergic mechanosensory transduction has been proposed for visceral pain, where ATP released from epithelial cells lining the bladder, ureter, and intestine during distension acts on P2X3 and P2X2/3, and possibly P2Y, receptors on subepithelial sensory nerve fibers to send messages to the pain centers in the brain as well as initiating local reflexes. P1, P2X, and P2Y receptors also appear to be involved in nociceptive neural pathways in the spinal cord. P2X4 receptors on spinal microglia have been implicated in allodynia. The involvement of purinergic signaling in long-term neuropathic pain and inflammation as well as acute pain is discussed as well as the development of P2 receptor antagonists as novel analgesics.

Diagnosis and management of patients with overactive bladder syndrome and abnormal detrusor activity

Overactive bladder syndrome (OABS) is a widely recognized syndrome with symptoms that can include urinary urgency, frequency, nocturia, and incontinence. Although there may be several causative factors for OABS, detrusor overactivity is the most common. In addition, urinary incontinence can also be due to a distinct but equally bothersome condition underactive bladder syndrome, or detrusor underactivity. The incomplete bladder emptying that characterizes detrusor underactivity often arises from impaired contractile function of the detrusor muscle. The variations in etiologies of the two syndromes necessitate patient evaluations tailored to individual symptom presentation. Increased awareness of the differences between the manifestations of OABS and underactive bladder syndrome call for specific approaches to the management of bladder dysfunction.

Pathophysiology and therapeutic potential of purinergic signaling

The concept of a purinergic signaling system, using purine nucleotides and nucleosides as extracellular messengers, was first proposed over 30 years ago. After a brief introduction and update of purinoceptor subtypes, this article focuses on the diverse pathophysiological roles of purines and pyrimidines as signaling molecules. These molecules mediate short-term (acute) signaling functions in neurotransmission, mechanosensory transduction, secretion and vasodilatation, and long-term (chronic) signaling functions in cell proliferation, differentiation, and death involved in development and regeneration. Plasticity of purinoceptor expression in pathological conditions is frequently observed, including an increase in the purinergic component of autonomic cotransmission. Recent advances in therapies using purinergic-related drugs in a wide range of pathological conditions will be addressed with speculation on future developments in the field.

Differential effects of the antimuscarinic agents darifenacin and oxybutynin ER on memory in older subjects

OBJECTIVES

To investigate the effects of darifenacin controlled-release (CR) and oxybutynin extended-release (ER) on cognitive function (particularly memory) in older subjects.

METHODS

Healthy subjects (n=150) >/=60 years were randomised to darifenacin, oxybutynin ER or placebo in a multicentre, double-blind, double-dummy, parallel-group, 3-week study. Doses were administered according to US labels: oxybutynin ER 10mg once daily (od), increasing to 15mg od then 20mg od by week 3; darifenacin 7.5mg od in weeks 1 and 2, then 15mg od in week 3. The primary end point was accuracy on the Name-Face Association Test (delayed recall) at week 3.

RESULTS

Results of the Name-Face Association Test at week 3 showed no significant difference between darifenacin and placebo on delayed recall (mean difference, -0.06, p=0.908). In contrast, oxybutynin ER resulted in memory impairment, with significantly lower scores than placebo and darifenacin (mean differences, -1.30, p=0.011 and -1.24, p=0.022, respectively) for delayed recall on the Name-Face Association Test at week 3. Additional tests of delayed recall indicated significant memory impairment with oxybutynin ER versus placebo at certain time points, whereas darifenacin was similar to placebo. No between-treatment differences were detected in self-rated memory, demonstrating that subjects were unaware of memory deterioration.

CONCLUSIONS

While darifenacin had no significant effects on memory versus placebo, oxybutynin ER caused significant memory deterioration (magnitude of effect comparable to brain aging of 10 years). The results also demonstrate that subjects may not recognise/report memory deterioration.